Mobile device locating using long term evolution signals

Abstract

The described examples provide a system and methods for identifying a location of a mobile device within an indoor venue using cellular communication signals obtained while the mobile device is within the indoor venue. An array of antennas arranged within the indoor venue detects cellular communication signals transmitted by the mobile device. The detected cellular communication signals have detectable and measurable signal parameters that allow the location of the mobile device within the indoor venue and an identifier of the mobile device to be determined. The determined identifier of the mobile device may also be used to identify the mobile device subscriber. The mobile device indoor location information may be used to update an anonymized subscriber profile associated with the mobile device subscriber.

What is claimed is: 
     
       1. A method, comprising:
 detecting, by a plurality of antennas within an indoor venue, a mobile communication data signal transmitted by a mobile device; 
 identifying a time slot and frequency sub-carrier associated with the detected mobile communication data signal; 
 measuring a signal parameter of the mobile communication data signal detected by each of the plurality of antennas in the time slot and frequency sub-carrier; 
 determining, using the signal parameter measured by each of the plurality of antennas, information identifying an approximate location of the mobile device inside the indoor venue; 
 determining, using the time slot and frequency sub-carrier, an identity associated with the mobile device; and 
 storing the information identifying the approximate location of to the mobile device and the time slot in a location log associated with the mobile device. 
 
     
     
       2. The method of  claim 1 , further comprising:
 retrieving from a data storage a subscriber profile associated with the mobile device; 
 obtaining, from the location log, the information identifying the approximate location of the mobile device; and 
 updating the subscriber profile using the information identifying the approximate location of the mobile device. 
 
     
     
       3. The method of  claim 1 , wherein the mobile communication data signal is a radio resource connection request transmitted in the time slot via the frequency sub-carrier and contains a temporary identifier assigned to the mobile device. 
     
     
       4. The method of  claim 1 , wherein the mobile communication data signal is an acknowledgement signal indicating that the mobile device has decoded data transmitted to the mobile device. 
     
     
       5. The method of  claim 1 , wherein the mobile communication data signal is a negative acknowledgement signal indicating that the mobile device is unable to decode data transmitted to the mobile device. 
     
     
       6. The method of  claim 1 , wherein the mobile communication data signal is any communication transmitted by the mobile device to a cellular communication management device. 
     
     
       7. The method of  claim 1 , further comprising:
 requesting, via a venue specific communication path with a cellular communication management device in a cellular network, data including a permanent mobile device identifier corresponding to the time slot and frequency sub-carrier in which the mobile device is communicating; 
 in response to the request, receiving from the cellular communication management device the permanent identifier of the mobile device; 
 determining an approximate location of the mobile device within a boundary of the indoor venue whenever the mobile device outputs a mobile communication data signal in the identified time slot and sub-carrier frequency to communicate with the cellular network; 
 generating a location log entry in the location log based on the determined approximate location of the mobile device; and 
 outputting at least some location information from the generated location log entry to a mobile device subscriber profile database. 
 
     
     
       8. The method of  claim 1 , wherein determining the identity associated with the mobile device further comprises:
 receiving, from the mobile device, the mobile communication data signal transmitted at the time slot and on the sub-carrier frequency, wherein the mobile communication data signal is an uplink data packet that includes a temporary mobile device identifier; and 
 receiving from a cellular communication management device a permanent mobile device identifier that corresponds to the temporary mobile device identifier. 
 
     
     
       9. The method of  claim 8 , wherein the mobile communication data signal transmitted by the mobile device in the time slot and on the sub-carrier frequency is an acknowledgement signal transmitted in response to a data signal transmitted in a physical downlink shared channel. 
     
     
       10. The method of  claim 1 , wherein the location log contains a plurality of data entries indicating approximate locations within the indoor venue from which the mobile device outputted a signal in the time slot and sub-carrier frequency to a cellular network. 
     
     
       11. The method of  claim 1 , wherein determining the information identifying the approximate location of the mobile device inside the indoor venue comprises:
 receiving the mobile communication data signal transmitted from the mobile device by at least two antennas located within an interior of the indoor venue; and 
 based on the signal parameter of the received signal at each of the at least two antennas and a known position of each of the at least two antennas, determining coordinates of the approximate location of the mobile device within the indoor venue. 
 
     
     
       12. The method of  claim 11 , wherein the signal parameter is signal strength. 
     
     
       13. The method of  claim 1 , further comprising:
 generating a location log entry for the mobile device using the identified time slot and frequency sub-carrier as a reference to the mobile device, wherein storing the information identifying the approximate location of the mobile device includes storing coordinates of the approximate location in the location log entry. 
 
     
     
       14. The method of  claim 1 , further comprising:
 in response to receiving the mobile communication data signal, determining an indication of an approximate amount of time that the mobile device spent at the determined approximate location. 
 
     
     
       15. The method of  claim 1 , further comprising:
 identifying coordinates of the mobile device in a coordinate system specific to the indoor venue; 
 comparing the identified coordinates of the mobile device to a layout map of the indoor venue, wherein the layout map includes a relative position of features within the indoor venue overlaying the indoor venue-specific coordinate system; and 
 based on the comparison, determining a specific position within the indoor venue of the mobile device. 
 
     
     
       16. A system, comprising:
 a controller including a processor and cellular communication transceiver; 
 a data storage device coupled to the controller, and 
 a plurality of antennas located indoors at an indoor venue, wherein each of the plurality of antennas is communicatively coupled to the controller via the cellular communication transceiver, 
 wherein the processor is configured to:
 receive, at a specific time slot and frequency sub-carrier in a cellular communication protocol, a cellular signal from a mobile device at the plurality of antennas within the indoor venue; 
 determine, using the specific time slot and frequency sub-carrier, an identity associated with the mobile device; 
 retrieve a subscriber profile associated with the mobile device; 
 in response to retrieving the subscriber profile, identify, using an indoor venue-specific coordinate system, coordinates of the mobile device in the indoor venue using a cellular signal strength relative to each of the respective plurality of antennas that received the cellular signal; 
 compare the identified mobile device coordinates to a layout map of the indoor venue, wherein the layout map includes a schematic layout diagram of elements within the indoor venue overlaying the indoor venue-specific coordinate system; and 
 based on the comparison, determine a specific location within the indoor venue corresponding to the identified coordinates of the mobile device. 
 
 
     
     
       17. The system of  claim 16 , wherein the processor is further configured to:
 modify the subscriber profile using the determined specific location of the mobile device within the indoor venue. 
 
     
     
       18. The system of  claim 16 , wherein the processor is further configured to:
 in response to receiving the cellular signal, determine an approximate amount of time that the mobile device spent at the determined specific location. 
 
     
     
       19. The system of  claim 16 , wherein the processor is further configured to:
 at a subsequent time, receive, at a different time slot and frequency sub-carrier in a cellular communication protocol, another cellular signal from the mobile device at the plurality of antennas within the indoor venue, wherein the different time slot and frequency sub-carrier were assigned to the mobile device for transmitting the other cellular signal; 
 in response to receiving the other cellular signal in the different time slot and frequency sub-carrier, identify second coordinates of the mobile device in the venue-specific coordinate system; 
 compare the identified mobile device second coordinates to the layout map of the indoor venue, wherein the layout map includes a relative position of features within the indoor venue overlaying the indoor venue-specific coordinate system; and 
 based on the comparison of the second mobile device second coordinates to the layout map, determine a subsequent specific location within the indoor venue of the mobile device when the mobile device transmitted the other cellular signal. 
 
     
     
       20. The system of  claim 19 , wherein the processor is further configured to:
 determine that the specific location and the subsequent specific location both correspond to the mobile device; and 
 update a subscriber profile related to the mobile device with the specific location and the subsequent specific location.